Getting the data
Data was collected from https://github.com/CSSEGISandData/COVID-19.
The code for this analysis is avaiable on github.
Countries with more than 500 cases:
The following shows the onset of the COVID19 pandemic in all countries which reported up to today at least 500 cases, starting from March 01, 2020. 
And on log-scale: 
It is clearly visible, that in most of the countries the increase in cases is following an exponential growth.
Prediction for Germany
If we assume an exponential growth, we can use the data available and see what to expect in the next couple of days. I know that the circumstances can change very quickly, which is why I only provide the prediction for the next five days: 